Method for forming variable width isolation structures

摘要

An isolation structure as well as a method for using and fabricating an isolation structure in an active layer deposited on a substrate the method of fabrication including the steps of forming a buried oxide layer in the active layer adjacent the substrate, forming an isolation trench in the active layer by etching at least up to and optionally into the substrate, forming a dielectric isolation layer on the exposed surfaces of the trench, removing the dielectric isolation layer from the bottom of the trench, and forming an isolation structure by epitaxially growing monocrystalline silicon in the trench.